Gaging Computers: Doing More with Less

Giving operators a single user interface that implements all aspects of gaging helps them become more productive and reduces the potential for error.

Columns
From:
12/15/2011
Modern Machine Shop,
George
Schuetz

Editor's Commentary

From the monthly column "Quality Gaging Tips."

When you think about it, a lot of data has become available to the process engineer on the shop floor. Starting 50 years ago with in-process charting, data has grown exponentially in electronics and gaging. Almost all gaging types now have a digital version—and once you go digital, you have the ability to send measuring results to a system that can collect and manage them. In fact, this has become the de facto method for collecting gaging data: The operator takes a measurement and sees the results on the gage, but the system takes those results and puts them into their proper bins.

The proliferation of personal computers (PCs) and the fact that most people are comfortable using them has increased their availability in manufacturing and quality areas. PCs are rarely necessities for standard dimensional measurements, although almost any application can be enhanced through the use of PC-based gaging software. While the use of “gaging computers” cannot serve as a substitute for sound gaging practice, the potential benefits they offer are greater and the barriers to entry are lower than ever.

Modern gaging computer systems can integrate all the different gaging interface types into a single system. Gaging computer systems are now handling many of these individual gaging points by integrating all the different gage interface types into one base computer. Now, instead of a number of standalone air gages and linear variable differential transformer (LVDT)-style bench amplifiers, quality personnel have access to gaging computers with interfaces available to configure all input types. This is where less becomes more for the gaging process. The computer now provides the visual indication for the operator to look at these individual displays and watch the changing tolerance colors and the data being acquired. Thus, the gaging computer has become the display, data collection device, results classifier and overall guide to the measurement process. This is a much more cost-effective solution to dealing with multiple gage input requirements.

Automating the gaging process is another benefit of the gaging system for both the operator and the process engineer. For complex measuring functions—say measuring 20 features on an engine block after a complex machining operation—the gaging computer will provide a “guided sequence” that leads the operator through the gaging routine. The routine can not only instruct the operator which gage to use and where to place it, but also provide an indication of the results and what to do if the results are not what they are supposed to be. At the same time, the results of the measurements are stored in the background for continuous review and analysis of the process from almost anywhere in the world.

It is easy to see how the centralization of gaging can reduce the cost of the gaging station by reducing the number of standalone signal processing units—a trend that will certainly continue.

What about those other gaging stations that are complicated in their own right and need their own dedicated computers to run and analyze results? These include stations for surface-finish, shaft and/or form measurement. It has always been a challenge to integrate these various systems into the guided sequence when each has its own, unique operating system. However, advances are being made to effect this integration. PCs now have enough horsepower to run multiple, very-complex applications quickly on the same platform. This eliminates the need for separate computers running special gaging software.

The concept is this: An overall gaging program runs a guided sequence, leads the operator through the gaging routine, collects the data and analyzes the results. Rather than telling the user to walk over to the surface-finish system, do his or her task and transmit the results, there is no separate surface-finish station. Instead, the surface-finish system is integrated into the same gaging computer system, and the surface-finish software runs in the background. The gaging software “calls up” the surface-finish program and activates one of its application programs. When the guided sequence calls for a surface check, it links to the software. The operator makes the check, and the results are collected. Then it’s back to the rest of the sequence, which is transparent to the operator and others who are using the same style of user interface. So, one computer does more work and eliminates the cost of using multiple computer systems. Even more is being done with less.

The process engineer on the shop floor is responsible for many tasks: producing parts, running machines, programming parts, doing preventive maintenance and making decisions about part quality. So, it’s important to make his or her job as easy and efficient as possible. Giving operators a single user interface that implements all their gaging, from calipers to complex surface systems, and leading them through the measurement routines makes life easy, reduces the potential for error, and provides a cost-effective way to monitor the gaging process.

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